Mediating effects of dietary intake on associations of TV viewing, body mass index and metabolic syndrome in adolescents

OBJECTIVE: Evidence suggests that TV viewing is associated with body mass index (BMI) and metabolic syndrome (MetS) in adolescents. However, it is unclear whether dietary intake mediates these relationships.

METHODS: A cross-sectional analysis was conducted in adolescents (12-19 years) participating in the 2003-2006 United States National Health and Nutrition Examination Survey. BMI z scores (zBMI) (n = 3,161) and MetS (n = 1,379) were calculated using age- and sex-specific criteria for adolescents. TV viewing (h/day) was measured via a self-reported questionnaire, and dietary intake was assessed using two 24-h recalls. Using the MacKinnon method, a series of mediation analyses were conducted examining five dietary mediators (total energy intake, fruit and vegetable intake, discretionary snacks, sugar-sweetened beverages and diet quality) of the relationships between TV viewing and zBMI and MetS.

RESULTS: Small positive relationships were observed between TV viewing and zBMI (β = 0.99, p < 0.001) and TV viewing and MetS (OR = 1.18, p = 0.046). No dietary element appeared to mediate the relationship between TV viewing and zBMI. However, sugar-sweetened beverage consumption and fruit and vegetable intake partially mediated the relationship between TV viewing and MetS, explaining 8.7% and 4.1% of the relationship, respectively.

CONCLUSIONS: These findings highlight the complexity of the relationships between TV viewing, dietary intake and cardiometabolic health outcomes, and that TV viewing should remain a target for interventions.

A quadtree driven image fusion quality assessment

In this paper a new method to compute saliency of source images is presented. This work is an extension to universal quality index founded by Wang and Bovik and improved by Piella. It defines the saliency according to the change of topology of quadratic tree decomposition between source images and the fused image. The saliency function provides higher weight for the tree nodes that differs more in the fused image in terms topology. Quadratic tree decomposition provides an easy and systematic way to add a saliency factor based on the segmented regions in the images.

Sleep quality and depression during pregnancy: a prospective study

For the first time, the relationship between depressive symptoms and sleep quality was explored prospectively during pregnancy. Participants (n = 273) completed the Pittsburgh Sleep Quality Index and Beck Depression Inventory at three 8-week intervals, starting from 15–23 weeks gestation. In addition to sleep quality and depression remaining relatively stable during pregnancy, findings revealed that sleep quality earlier in pregnancy predicted higher levels of depressive symptoms at later stage in pregnancy (after controlling for prior depression levels). In contrast, there was no evidence to suggest that depressive symptoms earlier in pregnancy impacted on sleep quality later on. Given that depressive symptomatology can lead to major depression and given the prevalence of pre- and postnatal depression, our findings suggest that screening for sleep problems during pregnancy may be of clinical significance.

Examination of a multi-factorial model of body-related experiences during pregnancy : the relationships among physical symptoms, sleep quality, depression, self-esteem, and negative body attitudes

The aim of this cross-sectional study was to investigate relationships among women's body attitudes, physical symptoms, self-esteem, depression, and sleep quality during pregnancy. Pregnant women (N = 215) at 15–25 weeks gestation completed a questionnaire including four body image subscales assessing self-reported feeling fat, attractiveness, strength/fitness, and salience of weight and shape. Women reported on 29 pregnancy-related physical complaints, and completed the Beck Depression Inventory, Rosenberg Self-esteem Scale, and Pittsburgh Sleep Quality Index. In regressions, controlling for retrospective reports of body image, more frequent and intense physical symptoms were related to viewing the self as less strong/fit, and to poorer sleep quality and more depressive symptoms. In a multi-factorial model extending previous research, paths were found from sleep quality to depressive symptoms to self-esteem; self-esteem was found to be a mediator associated with lower scores on feeling fat and salience of weight and shape, and on higher perceived attractiveness.

Depression, diet and exercise

Unhealthy lifestyle behaviour is driving an increase in the burden of chronic non-communicable diseases worldwide.

Recent evidence suggests that poor diet and a lack of exercise contribute to the genesis and course of depression.

While studies examining dietary improvement as a treatment strategy in depression are lacking, epidemiological evidence clearly points to diet quality being of importance to the risk of depression.

Exercise has been shown to be an effective treatment strategy for depression, but this is not reflected in treatment guidelines, and increased physical activity is not routinely encouraged when managing depression in clinical practice.

Recommendations regarding dietary improvement, increases in physical activity and smoking cessation should be routinely given to patients with depression.

Specialised and detailed advice may not be necessary. Recommendations should focus on following national guidelines for healthy eating and physical activity.

The impact of interventions to prevent obesity or improve obesity related behaviours in children (0-5 years) from socioeconomically disadvantaged and/or indigenous families: a systematic review

Background
Children from disadvantaged families including those from low socioeconomic backgrounds and Indigenous families have higher rates of obesity, making early intervention a priority. The aim of this study was to systematically review the literature to examine the effectiveness of interventions to prevent obesity or improve obesity related behaviours in children 0-5 years from socioeconomically disadvantaged or Indigenous families.

Methods
Searches of major electronic databases identified articles published from 1993–2013 targeting feeding practices, anthropometric, diet, activity or sedentary behaviour outcomes. This was supplemented with snowballing from existing reviews and primary studies. Data extraction was undertaken by one author and cross checked by another. Quality assessments included both internal and external validity.

Results
Thirty-two studies were identified, with only two (both low quality) in Indigenous groups. Fourteen studies had a primary aim to prevent obesity. Mean differences between intervention and control groups ranged from -0.29 kg/m2 to -0.54 kg/m2 for body mass index (BMI) and -2.9 to -25.6% for the prevalence of overweight/obesity. Interventions initiated in infancy (under two years) had a positive impact on obesity related behaviours (e.g. diet quality) but few measured the longer-term impact on healthy weight gain. Findings amongst pre-schoolers (3–5 years) were mixed, with the more successful interventions requiring high levels of parental engagement, use of behaviour change techniques, a focus on skill building and links to community resources. Less than 10% of studies were high quality. Future studies should focus on improving study quality, including follow-up of longer-term anthropometric outcomes, assessments of cost effectiveness, acceptability in target populations and potential for implementation in routine service delivery.

Conclusion
There is an urgent need for further research on effective obesity prevention interventions for Indigenous children. The findings from the growing body of intervention research focusing on obesity prevention amongst young children from socioeconomically disadvantaged families suggest intervention effects are modest but promising. Further high quality studies with longer term follow up are required.

'Better health choices' by telephone: a feasibility trial of improving diet and physical activity in people diagnosed with psychotic disorders

The study objective was to evaluate the feasibility of a telephone delivered intervention consisting of motivational interviewing and cognitive behavioural strategies aimed at improving diet and physical activity in people diagnosed with psychotic disorders. Twenty participants diagnosed with a non-acute psychotic disorder were recruited. The intervention consisted of eight telephone delivered sessions targeting fruit and vegetable (F&V) consumption and leisure screen time, as well as smoking and alcohol use (as appropriate). F&V frequency and variety, and overall diet quality (measured by the Australian Recommended Food Score, ARFS), leisure screen time, overall sitting and walking time, smoking, alcohol consumption, mood, quality of life, and global functioning were examined before and 4-weeks post-treatment. Nineteen participants (95%) completed all intervention sessions, and 17 (85%) completed follow-up assessments. Significant increases from baseline to post-treatment were seen in ARFS fruit, vegetable and overall diet quality scores, quality of life and global functioning. Significant reductions in leisure screen time and overall sitting time were also seen. Results indicated that a telephone delivered intervention targeting key cardiovascular disease risk behaviours appears to be feasible and relatively effective in the short-term for people diagnosed with psychosis. A randomized controlled trial is warranted to replicate and extend these findings.

The impact of whole-of-diet interventions on depression and anxiety: a systematic review of randomised controlled trials

Non-pharmacological approaches to the treatment of depression and anxiety are of increasing importance, with emerging evidence supporting a role for lifestyle factors in the development of these disorders. Observational evidence supports a relationship between habitual diet quality and depression. Less is known about the causative effects of diet on mental health outcomes. Therefore a systematic review was undertaken of randomised controlled trials of dietary interventions that used depression and/or anxiety outcomes and sought to identify characteristics of programme success.

A dietary guideline adherence score is positively associated with dietary biomarkers but not lipid profile in healthy children

BACKGROUND: Whether dietary indexes are associated with biomarkers of children's dietary intake is unclear. OBJECTIVE: The study aim was to examine the relations between diet quality and selected plasma biomarkers of dietary intake and serum lipid profile. METHODS: The study sample consisted of 130 children aged 4-13 y (mean ± SD: 8.6 ± 2.9 y) derived by using baseline data from an intervention study. The Dietary Guideline Index for Children and Adolescents (DGI-CA) comprises the following 11 components with age-specific criteria: 5 core food groups, whole-grain bread, reduced-fat dairy foods, discretionary foods (nutrient poor; high in saturated fat, salt, and added sugar), healthy fats/oils, water, and diet variety (possible score of 100). A higher score reflects greater compliance with dietary guidelines. Venous blood was collected for measurements of serum lipids, fatty acid composition, plasma carotenoids, lutein, lycopene, and α-tocopherol. Linear regression was used to examine the relation between DGI-CA score (independent variable) and concentrations of biomarkers by using the log-transformed variable (outcome), controlling for confounders. RESULTS: DGI-CA score was positively associated (P < 0.05) with plasma concentrations of lutein (standardized β = 0.17), α-carotene (standardized β = 0.28), β-carotene (standardized β = 0.26), and n-3 (ω-3) fatty acids (standardized β = 0.51) and inversely associated with plasma concentrations of lycopene (standardized β = -0.23) and stearic acid (18:0) (standardized β = -0.22). No association was observed between diet quality and α-tocopherol, n-6 fatty acids, or serum lipid profile (all P > 0.05). CONCLUSION: Diet quality, conceptualized as adherence to national dietary guidelines, is cross-sectionally associated with plasma biomarkers of dietary exposure but not serum lipid profile. This trial was registered with the Australia New Zealand Clinical Trial Registry (www.anztr.org.au) as ACTRN12609000453280.

Does reverse causality explain the relationship between diet and depression?

BACKGROUND: Observational studies have repeatedly demonstrated relationships between habitual diet quality and depression. However, whilst reverse causality has not been the identified mechanism for these associations in prospective studies, the relationship between diet and depression is likely complex and bidirectional. Thus explicit investigation of the reverse causality hypothesis is warranted. METHODS: Data were drawn from the Personality and Total Health (PATH) Through Life Study, a longitudinal community survey following three age cohorts from Australia. Analyses evaluated the relationships between past depression and treatment, current depressive symptoms and dietary patterns. RESULTS: Individuals with current depression had lower scores on a healthy dietary pattern; however, those who had been previously depressed and sought treatment had higher scores on the healthy dietary pattern at the later baseline assessment. Moreover, those who had reported prior, but not current, depression also had lower scores on the western dietary pattern than those without prior depression, regardless of whether they had been previously treated for their symptoms. LIMITATIONS: Self-report data and possible recall bias limit our conclusions. CONCLUSIONS: In this study, prior depression was associated with better quality diets at the later time point. Thus, while current depression is associated with poorer dietary habits, a history of depression may prompt healthier dietary behaviours in the long term. Given the demonstrated relationships between diet quality and depressive illness, clinicians should advocate dietary improvement for their patients with depression and should not be pessimistic about the likelihood of adherence to such recommendations.

Western diet is associated with a smaller hippocampus: a longitudinal investigation

Background: Recent meta-analyses confirm a relationship between diet quality and both depression and cognitive health in adults. While the biological pathways that underpin these relationships are likely multitudinous, extensive evidence from animal studies points to the involvement of the hippocampus. The aim of this study was to examine the association between dietary patterns and hippocampal volume in humans, and to assess whether diet was associated with differential rates of hippocampal atrophy over time. Methods: Data were drawn from the Personality and Total Health Through Life Study and focused on a subsample of the cohort (n = 255) who were aged 60-64 years at baseline in 2001, completed a food frequency questionnaire, and underwent two magnetic resonance imaging scans approximately 4 years apart. Longitudinal generalized estimating equation linear regression models were used to assess the association between dietary factors and left and right hippocampal volumes over time. Results: Every one standard deviation increase in healthy "prudent" dietary pattern was associated with a 45.7 mm³ (standard error 22.9 mm³) larger left hippocampal volume, while higher consumption of an unhealthy "Western" dietary pattern was (independently) associated with a 52.6 mm³ (SE 26.6 mm³) smaller left hippocampal volume. These relationships were independent of covariates including age, gender, education, labour-force status, depressive symptoms and medication, physical activity, smoking, hypertension and diabetes. While hippocampal volume declined over time, there was no evidence that dietary patterns influenced this decline. No relationships were observed between dietary patterns and right hippocampal volume. Conclusions: Lower intakes of nutrient-dense foods and higher intakes of unhealthy foods are each independently associated with smaller left hippocampal volume. To our knowledge, this is the first human study to demonstrate associations between diet and hippocampal volume concordant with data previously observed in animal models.

A review of the relationship between socioeconomic position and the early-life predictors of obesity

A range of important early-life predictors of later obesity have been identified. Children of lower socioeconomic position (SEP) have a steeper weight gain trajectory from birth with a strong socioeconomic gradient in child and adult obesity prevalence. An assessment of the association between SEP and the early-life predictors of obesity has been lacking. The review involved a two-stage process: Part 1, using previously published systematic reviews, we developed a list of the potentially modifiable determinants of obesity observable in the pre-natal, peri-natal or post-natal (pre-school) periods; and part 2, conducting a literature review of evidence for socioeconomic patterning in the determinants identified in part 1. Strong evidence was found for an inverse relationship between SEP and (1) pre-natal risk factors (pre-pregnancy maternal body mass index (BMI), diabetes and pre-pregnancy diet), (2) antenatal/peri natal risk factors (smoking during pregnancy and low birth weight) and (3) early-life nutrition (including breastfeeding initiation and duration, early introduction of solids, maternal and infant diet quality, and some aspects of the home food environment), and television viewing in young children. Less strong evidence (because of a lack of studies for some factors) was found for paternal BMI, maternal weight gain during pregnancy, child sleep duration, high birth weight and lack of physical activity in young children. A strong socioeconomic gradient exists for the majority of the early-life predictors of obesity suggesting that the die is cast very early in life (even pre-conception). Lifestyle interventions targeting disadvantaged women at or before child-bearing age may therefore be particularly important in reducing inequality. Given the likely challenges of reaching this target population, it may be that during pregnancy and their child's early years are more feasible windows for engagement.

Higher adherence to the Australian dietary guidelines is associated with better mental health status among Australian adult first-time mothers

Background: Mental health disorders are a leading cause of disability worldwide, including in first-time mothers. Understanding the associations between diet and depressive symptoms could assist in improving mental health status in this group. Objective: Our aim was to determine the association between diet quality, fruit, vegetable, and fish consumption and depressive symptoms in first-time mothers aged 19 to 45 years.

Design: We analyzed cross-sectional, baseline data (3 months postpartum) from the Melbourne InFANT (Infant Feeding, Activity, and Nutrition Trial) Extend Program.

Participants/setting: Participants were first-time Australian mothers aged 19 to 45 years from the Geelong and Melbourne regions of Victoria, Australia (n=457).

Main outcome measures: A self-administered, 137-item food frequency questionnaire assessed dietary intake over the past year. Adherence to the 2013 Australian Dietary Guidelines was assessed using the Dietary Guideline Index as a measure of diet quality. Depressive symptoms were determined using the Center for Epidemiologic Studies Depression Scale.

Statistical analysis performed: Relationships between diet quality, fruit, vegetable, and fish intake and depressive symptoms were investigated using linear regression adjusted for relevant covariates (age, smoking status, sleep quality, education, physical activity status, and body mass index).

Results: Better diet quality, as indicated by a higher score on the Dietary Guideline Index, was associated with lower depressive symptoms after adjusting for relevant covariates (β=-.034; 95% CI -.056 to -0.012). There were no other associations between dietary intake and depressive symptoms.

Conclusions: Adherence to the Australian Dietary Guidelines was associated with better mental health status among first-time mothers. Further research, including longitudinal and intervention studies, are required to determine causality between dietary intake and depressive symptoms, which might help inform future public health nutrition programs for this target group.

Classification tree analysis of postal questionnaire data to identify risk of excessive gestational weight gain

OBJECTIVE: overweight/obese weight status during pregnancy increases risk of a range of adverse health outcomes for mother and child. Whereas identification of those who are overweight/obese pre-pregnancy and in early pregnancy is straightforward, prediction of who will experience excessive gestational weight gain (EGWG), and thus be at greater risk of becoming overweight or obese during pregnancy is more challenging. The present study sought to better identify those at risk of EGWG by exploring pre-pregnancy BMI as well as a range of psychosocial risk factors identified as risk factors in prior research. METHODS: 225 pregnant women completed self-reported via postal survey measures of height, weight, and psychosocial variables at 16-18 weeks gestation, and reported their weight again at 32-34 weeks to calculate GWG. Classification and regression tree analysis (CART) was used to find subgroups in the data with increased risk of EGWG based on their pre-pregnancy BMI and psychosocial risk factor scores at Time 1. FINDINGS: CART confirmed that self-reported BMI status was a strong predictor of EGWG risk for women who were overweight/obese pre-pregnancy. Normal weight women with low motivation to maintain a healthy diet and who reported lower levels of partner support were also at considerable risk of EGWG. IMPLICATIONS FOR PRACTICE: present findings offer support for inclusion of psychosocial measures (in addition to BMI) in early antenatal visits to detect risk of EGWG. However, these findings also underscore the need for further consideration of effect modifiers that place women at increased or decreased risk of EGWG. Proposed additional constructs are discussed to direct further theory-driven research.

Socioeconomic position and premature mortality in the AusDiab cohort of Australian adults

OBJECTIVES:
To determine the association of socioeconomic position indicators with mortality, without and with adjustment for modifiable risk factors.

METHODS:
We examined the relationships of 2 area-based indices and educational level with mortality among 9338 people (including 8094 younger than 70 years at baseline) of the Australian Diabetes Obesity and Lifestyle (AusDiab) from 1999-2000 until November 30, 2012.

RESULTS:
Age- and gender-adjusted premature mortality (death before age 70 years) was more likely among those living in the most disadvantaged areas versus least disadvantaged (hazard ratio [HR] = 1.48; 95% confidence interval [CI] = 1.08, 2.01), living in inner regional versus major urban areas (HR = 1.36; 95% CI = 1.07, 1.73), or having the lowest educational level versus the highest (HR = 1.64; 95% CI = 1.17, 2.30). The contribution of modifiable risk factors (smoking status, diet quality, physical activity, stress, cardiovascular risk factors) in the relationship between 1 area-based index or educational level and mortality was more apparent as age of death decreased.

CONCLUSIONS:
The relation of area-based socioeconomic position to premature mortality is partly mediated by behavioral and cardiovascular risk factors. Such results could influence public health policies.